"You haven’t mentioned what supplements you’re taking."
No and the OP has not also mentioned much about other related things such as sex......male or female.
I keep having to say this and I think I will make a keymap so that I can quickly post it the same reply [an idea which I will make a note of and make sure that I do so that I do not have to keep wasting time posting the exact same information].
L-glutamine cannot and will not fix "Leaky Gut" or more correctly Increase Digestive Permeability[IDP] which I have come up with from the medical term Increased Intestinal Permeability Syndrome. I suggest that you read Daniel ViPond's PhD thesis which was sponsored by an ME charity and is about "Leaky Gut" as a being a feature and cause. He makes an educated guess that IDP is caused by a pathogenic infection of the digestive system which I have known far more precisely than that since Jan 2014, just after he began his work. It is far bigger than just this but I will not go into that here.
Frequent Urination is fairly common in the ME community and is one feature of the consequences which I will not state because it is one that I have worked out which is not known so far. There can be different causes of frequent urination, Diabetes insipidus is one and there are others which relate to ME.
The insomnia is not directly related to the urination, it is very common with people with IDP and relates to it's effect on the Liver and stress hormone release which promotes wakefulness during the early hours. Histamine release also promotes insonmia.
One method to treat the urination is to use a Chinese herb called Tu Si Zi (cuscuta sinesis/Dodder seed) which is sometimes used with Gou Qi Zi (Fructus Lycii) commonly called Goji berry. This is known to reduce urination by supporting the HPA axis. I will not go into details how it does but it can work quite effectively. Reducing inflammation and lowering cortisol will help with sleep. That is a big task to accomplish. See the selfhacked website for items/supps and foods to do this in particular cytokine reduction/manipulation. Cordyceps works very well BTW if you can find a good product with a high beta-glucan content rather than polysaccharides.
There are books on the GAPS diet so I will not provide any additional info on that. I purchased the book by the maker of the diet long ago and did the diet for some time which I found interesting and quite enjoyable with the way that I made it. Boiling the bones is the hard part, I used a pressure cooker to do that and reduce the condensation. I then froze it in silicon bread baking trays.
BTW That will not fix it because it is caused by pathogen(s) which are biofilm protected. All the information on the web about "Leaky Gut" is false and incorrect and does not work for that reason, they all fail to treat the cause which is not related to tight junctions. Again I will not go into details from my 7+ years of research on this topic because researchers do not deserve any heads up on this, they are utterly incompetent IMO and do not deserve any recognition for stolen ideas. Also Daniel Viponds research was extremely disappointing AFAIAC because it was less than I had worked out at the beginning of his work.